Response of Fresh Forage, Dry Matter and Yield Components of Sorghum to Different level of Nitrogen and Cutting Height

BACKGROUND: Fertilizer management plays an important role for obtaining satisfactory yields and to increase crop productivity. Nitrogen is generally a limiting nutrient in crop production, and especially in sorghum, as it has been said to be the most responsive nutrient for its production. OBJECTIVES: Current study was conducted to assessment effect of urea fertilizer and cutting height on seed yield, its components and harvest index of Sorghum. METHODS: This research was carried out via split plot experiment based on randomized complete blocks design with three replications. The main factor included three level of urea fertilizer (200, 300 and 400 kg.ha-1) and three level of cutting height (7, 12 and 14 cm) belonged to subfactor. RESULT: According result of analysis of variance effect of urea fertilizer and cutting height on all measured traits (instead harvest index) was significant, but interaction effect of treatments on 1000-seed weight, fresh forage yield, harvest index, number of seed per panicle and number of fertile tiller was not significant. Mean comparison result of different level of urea fertilizer indicated that maximum amount of all measured traits belonged to 400 kg.ha-1 treatment. As for Duncan classification made with respect to different level of cutting height the highest amount of studied characteristics was for 7cm treatment. Evaluation mean comparison result of interaction effect of treatments revealed maximum seed yield (693 gr.m-2) was noted for 400 kg.ha-1 urea fertilizer and 7cm cutting height and lowest one (480 gr.m-2) belonged to 200 kg.ha-1 urea and 17cm treatment. Similar result was found for other traits. CONCLUSION: According result of current study 400 kg.ha-1 urea fertilizer and 7cm cutting height had the highest amount of studied traits, so it can be advice to producers.